De lancy kennedy



(No Model.)

' DE LANGY KENNEDY.

METAL PUNGH. No 267,751. Patented Nov. 21, 1882-;

WITNESSES 1.7V VEJV TOR .[lttorneysp UNITED STATES PAT NT FFICE.

DE LANOY KENNEDY, OF NEIV YORK, N. Y.

METAL-PUNCH.

SPECIFICATION forming part of Letters Patent No. 267,751, dated November21, 1882. Application filed May 11, 1882. (No model.) Patented in CanadaFebruary 17, 1880, No. 10,928.

To all whom it may concern Be it known that I, DE LANGY KENNEDY, of thecity, county, and State of New York, have invented certain new anduseful Improvements in Metal-Punches; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing bad to the accompanying drawings, and to the letters of referencemarked theron.

My present invention is an improvement upon that described in LettersPatent of the United States No. 161,Q68, granted to me April 13,1875,and'forms a part of the subject of Letters Patent of Canada No. 10,928,granted February 17, 1880. The characteristics of the punch constitutingthe invention patented in line. As a result of the use of my saidpatented invention there are comparatively no defieotion of the metalpunched, no elongation of the hole, and no appreciable differencevisible between the shape of the hole punched and the periphery of thepunch, whether-the latter .be round, square, or oval.

The first part of myinvention relates to forming the punch with a firstcutting-point at the periphery and a central bearing, and removing apart of the surface area or cutting-face of the tool between said point,so that the resistance met with during the cutting-stroke may, bereduced at the side of the punch first called into requisition and thestrain on the tool the better equalized.

The second part of my invention relates to providing the punch with twofirst cuttingpoints at opposite sides of the periphery, and uniting saidpoints by spirals, each of which extends one-half around thecircumference of the punch. In the punch, as constructed in accordancewith this part of my invention, a

. portion of the surface or cutting-face'area. of

the tool is removed between each first cuttingpoint and the centralhearing or narrow base.

' In the drawings, Figure l isa side view of a punch embodying myinvention from one point of observation. Fig. 2 is a similar view from asecond point ofobservation. Fig. 3 is a similar view from a third pointof observation. Fig. 4. is a similar view from a fourth point ofobservation. Fig. 5 is a plan of the punch. Fig. 6 is a plan view of thepunch constructed with two first cutting-points at the periphery,connected by spirals, as above mentioned. Figs. 7 and 8 are hereinafterreferred to.

Similar letters of reference indicate similar parts in the respectivefigures.

A is the punch, having a central bearing or narrow base, a, which, withthe center point, 1), forms the mechanical center of the tool. A guidingor easing edge is shown by c, uniting the first cutting'point d of theperiphery with i the spiral. The edge 0 serves to guide, ease, and clearthe tool during the cutting process, and at the same time greatlystrengthens the tool, which without said edge would be weak at thevertical line, which would unite the first cuttingpointdof the peripherywith the spiral. A portion, 6, of the area or cutting-face of the punchis removed, the resistance to the side of the punch from which theportion is taken being thereby lessened, the first cutting-point d ofthe periphery and the center bearing, a, doing the cutting work, beingnnretarded by the presence of an'intermediate body of metal, which wouldbe inoperative for useful work.

In Fig.6 the punch is shown with the double spiral before mentioned. Itwill be seen that the punch has two cutting-points at the pe- First.Less power is requiredto operate the I00 tool than that ordinarilydemanded, a firm bearing being obtained at the center, and the forcebeing expended progressively as the cut-- ting or shearing is done, andnot at one time, as with the common flat-faced punch.

Second. It is found that the tensile strength of the metal punched isless impaired when punched by the use of my invention than by theordinary means.

Third. It is found that the hole can be punched in the precise locationdesired without deflection in the plate.

Fourth. The hole punched is perfectly round or of the shape of thepunch, no elongation or distortion being seen, this desirable resultaccruing from the joint operation of the peripheral and central cuttingparts, the first cuttingpoint of the periphery operating simultaneouslywith the center bearing, and the force applied after the engagement ofthese parts with the metal to be punched being in a true perpendiculardirection. 7

I make no claim at this time for the cuttingedge of the punch extendingfrom the central point or bearing to the periphery, as that was claimedand allowed in my United States Patent of April 13, 1875.

I disclaim the constructions shown in plan view in Figs. 7 and 8. Inboth views no part of the area or cutting-face of the punch is removed,as at c in the other figures. In Fig. 7 the construction is that of asingle spiral vrith a central bearing or narrow base, and with no partof the area or cutting-face of the punch removed. In Fig.8 theconstruction is that of a double spiral, having also a central hearingor narrow base, with no part of the area or cutting-face of the punchremoved. The constructions shown in Figs. 7 and 8 have been in extensiveuse and on sale by me in this country for about five years, it having inpractice been found advantageous to modify the formation of the punchpatented to me in the United States, as aforesaid, in accordancetherewith. I therefore disclaim as a part of my present invention apunch having a center and a narrow flat area or initial cuttingfaceextending across the tool, such, in view of the said public use and saleby me, not being now, as I am advised, subject-matter for avalid patent.I also disclaim as a part of my present invention the constructioncovered by Letters Patent of the United States No. 189,043, granted tome April 3, 1877, for improvement in projectiles, in which is found acutting-edge extending radially. from the axis to the periphery andthence spirally around or partly around the periphery to-a pointperpendicular to that touched by theline radiating from the axis; but

I claim as my present in vention-- 1. In the spiral shearing-punch A,the cutting-face, having a part, 6, removed between the center and firstcutting-point of the periphery, substantially as and for the purpose setforth.

2. In the spiral shearing-punch A, two first I cutting-points atopposite sides of the periphery, united by spirals, the cutting-face,having parts 0, removed between the center and first cutting-points,substantiallyas and for the purpose set forth.

3. In the spiral shearingpunch A, a central bearing or narrowbase, a,and a center point.

my hand and seal this 11th day of May, 1882.

DE LANOY KENNEDY. Witnesses:

W. '1. Cons, A. DE FIGANIERE.

